A digital camera has a signal processor, a high-frequency detector, a sampling processor, and a compression processor. The signal processor generates luminance and color difference data on the basis of image-pixel signals read from an image sensor. The high-frequency detector detects high-frequency components in the color difference data. The sampling processor carries out a sampling process to the luminance and color difference data in accordance with a given ratio of sampling frequencies. Then, the compression processor compresses the sampled luminance and color difference data. When there is a relatively low number of high-frequency components in the color difference data, the sampling processor samples the color difference data with a low sampling frequency.